<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>修改对象内容</title>
</head>
<body>
    <div class="box">我是文字内容</div>
<script>
  const box=document.querySelector('.box')
  console.log(box.innerText)
  box.innerText='<em>我是一个盒子</em>'
  console.log(box.innerHTML)
  box.innerHTML='<h4>我是一个大盒子</h4>'
</script>
</body>
</html>